Log-skidding machine.



J. R. McGlFFERT.

LOG SKIDDING MACHINE.

APPLICATION FILED JAN. 17, 1914.

1 1 0,301. Patented Nov. 16, 1915.

2 SHEETS-SHEET I.

J. R. McGlFFERT.

LOG SKIDDING MACHINE.

APPLICATION FILED JAN. 11. 1914.

Patented Nov. 16, 1915.

2 SHEETS-SHEET 2.

TTC E VE/J COLUMBIA PLANOGRAPH CO.,WASH1NGTON. n. cy

pu'r union JOHN R. MCGIFFERT, OF DULUTH, MINNESOTA, ASSIGNOR T0 CLYDE IRON'WORKS, 0F DULUTH, MINNESOTA, A CORPORATION OF MAINE.

LOG-SKIDDING ACHIN Specification of Letters Patent.

Patented Nov;16, 1915.

Application filed January 17, 1914. Serial No. 812,641.

for booms which are to be used for the purpose of lifting and transporting heavy loads.

The invention is particularly adapted to. be used in connection with log skidding ma: chines, one form of which is, illustrated in the drawings, to behereinafter described, and the particular feature of the invention to which attention is called is the flexible mounting for the boom,,which absorbs all shocks and permits the guy lines whichmaintain the boom against lateral movement, to be kept tight at all times. 7

To the accomplishment of these and related' ends said invention then consists of'the means hereinafter fully described and par-v ticularly pointed out inthe claims.

The annexed drawings and the following description set forth indetail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

Figure 1 is a partial side elevation of a log skidding machine showing the attachment of my invention thereto; Fig. 2 is a plan view of the same, but omitting certain parts of the boom; Fig. 3 is a section on the line 33 in Fig; 2; Fig. i is a section on the line 4+4 in Fig. l; and Fig. 5. is a section on the line 55 in Fig. l.

The general features of the log skidding machine, are too well known to require detailed explanation in this connection, the ma-, chine comprising a frame or car 1 which may be moved over a suitable track 2, there being mounted upon the car suitable drums for the purpose of controlling movement of the different cables which are required in the operation of the machine- At one end of the machine Ipivotallymount'about a sub stantially verticalaxisa horizontal member 5 which extends on either side of its axis, the ends of such member being engaged by resilient restraining means which will preferably take the form of a plurality of compression sprlngs 6 as here illustrated for the purpose of normally maintaining such member in a predetermined position. These restraining means are, however, adapted to permit the member to oscillate slightly about its axis under any abnormal rotative pressure. The precise mounting for the compression springs is notimportant but I have here shown them as being mounted horizontally against suitable backing plates 7 attached, to the car frame.

The boomin the present machine is preferably of A-form, the twov legs 8 in such boom being pivotally connected at their lower ends to the two, extending ends 9 of the member 5 on the frame, such pivotal connection being about a horizontalaxis. Mounted just back of the springs 6 upon the frame is a second A-boom or frame 10 extending vertically upward and to the'npper end or peak 11 of such frame is pivotally attached about a substan:

tially vertical axis, which is substantially alined with the axis of the member 5, asingle bar or memberlQwhich vextends outwardly V and is attached at its outer end to the peak 13 of the main boom. The legs of the boom and the outWardlyextending member are maintained in such rigid relation bymeans of other lugs or angle bars attached to the same at intervals along their length, thus.

providing arigid construction although permitting the boom to oscillate very slightly in a lateral direction and permitting also the rigid support or upper member to oscil-v late simultaneously therewith. The purpose ofthisresilient mounting for the boom will be seen from an inspection of" the cables which are supported at different points upon suitable. sheaves from the boom.

The car is first moved to a suitable point by means of the car propelling means mounted on the car itself. The boom is then braced against lateral movement by means of several guy wires or cables lt operated by drums 16 upon the frame and extending in divergent directions on. oneside of the peak 13 of the boom. These guy wires 14 are usually attached to stumps or trees, and

. if any great pressure isput' upon them they cut into the. tree or stump and thus become slightly slack. A considerable pressure will be put upon these guy wires since on the other side of the boom there'extends a trolley cable 15 upon which a carriage is mounted, the carriage bearing thereover a skidding line 17 which is operated by a drum 18 upon the frame as indicated. The

skidding linel7 when attached to a log or.

other load, and when drawn in, exerts a great amount of pressure on the carriage 20" tending to move the same toward the boom, or if this is prevented (as it, is), to move the carriage down, thus stretching the trolley cable and tending to move the boom to the right. If there is the slightest amount of slackness in the guy wires, the boom re- --sponds to the pressure in the trolley and slips to the right. It will be seen that the boom and support are practically a rigid structure which isso mounted that it may swing as a whole very slightly in a lateral direction about a substantially vertical axis.

Theresilient restraining means which control the oscillation of the horizontal member onthe car are provided to absorb any such slight oscillation of the boom and to prevent the same from passing its oscillation to the car itself. The compression springs are, of course, sufiiciently rigid to maintain the boom in its normal position against any ordinary strain. The wearon the machine a resulting. from the usual shocks isthus entirely. eliminated. e

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the fol-' lowing claims .or the equivalent of suchstated means be employed.

.I thereforeparticularly point out and C118- tinctly claim as my invention '1. The combination witha'suitable support; of a boom oscillatorily mounted thereon about a vertical axis; and restraining means adapted to normally maintain said boom in a predetermined position but to permitf oscillation of the same under abnormal lateral pressure in either direction.

2. The combination with a suitable sup port; of a boom oscillatorily mounted there- L on about a vertical axis; and resilient report; of a member oscillatorily mounted on the same about a vertical axis; a boom'attached to said member; and resilient restraining meansengaglng saidmember on either side of its axis and adapted to maintain said member in a predetermined position but to permit oscillation of the same under abnormal lateral pressure in either direction.

5'.v The combination with a suitable supportpoi a member oscillatorily mounted on the same about a vertical axis; an A'-b oom having its legs attached to the ends of said member, respectively; and resilient restraining means engaging said member on'either side of its axis and adapted to maintain said member in a predetermined'position but to permit oscillationot' the same under abnormal lateral pressure in either direction."

6. The combination with a suitable sup port; of a member oscillatorily mounted on the same about a vertical axis; an A-boom 7 having its legs attached to the ends of said member, respectively; and a plurality of V springs engagingsaid member on either side of its axis and adapt'ed to maintain said member in a predetermined position but to permit oscillationof the same under abnormal lateral pressure in either direction.

.7. The combination with a suitable support; of a member osoillatorily mounted on the same about a vertical axis; an A- boom having its legs attached to the ends of said member, respectively; and a plurality of horizontally disposed, compression springs engaging said member on either side of its axis and adapted to maintainsaid member in a'predetermined positionbut to permit. oscillatlon of the same under ab normal lateral pressure in either direction."

8'. The combination with a suitable support; of a boom pivotally mounted thereon about a vertical axis; resilient restraining means adapted to normally maintain said" boom in a predetermined position but to permit oscillation of the same underabnormal lateral pressure; and a rigid" supporting member for said boom, said member'being pivotally mounted about a vertical axis.

9. The combination with a suitable sup port; a boom pivotally mounted thereon about a vertical axis; resilient restraining means adapted to normally maintain said boom in a predetermined position but to per- '7 mitoscillation of the same under abnormal lateralpressure;and a supporting bar connected at one end to the peak of saidboom and having its other end pivotally connected to said support about a vertical axis. i

'10. The combination with a suitable support; of an A-boom pivotally mounted thereon about a verticalaxis; resilient re-..

straining means adapted to normally maintam said boom in a predeterminedposition but to permit oscillation of the same under abnormal lateral pressure; an A-frame mounted upon said support; and a rigid member attached at its outer end to the peak of said boom, said member having its inner end pivotally attached to the peak of said A-frame.

11. The combination With a suitable sup port; of an A-boom pivotally mounted thereon about a vertical axis; an A-frame 111011111," ed upon said support; and a rigid member attached to the peak of said boom, said member being pivotally attached to the peak of said A-frame about an axis substantially alined with the axis of said A-boom.

12. The combination With a suitable support; of an A-boom pivotally mounted thereon about a vertical axis; an A-frame mounted upon said support; a rigid member at tached to the peak of said boom, said member being pivotally attached to the peak of said A-frame about an axis substantially alined With the axis of said A-boom; and

means rigidly connecting said A-boom and said rigid member.

13. The, combination with a suitable support; of an A-boom pivotally mounted thereon about a vertical axis; an A-frame mounted upon said support; a rigid member attached to the peak of said boom, said member being pivotally attached to the peak of said A-frame about an axis substantially alined With the axis of said A-boom; means rigidly connecting said A-bbom and said rigid member; and resilient restraining means adapted to normally maintain said boom and said member in a predetermined position but to permit oscillation of the same under abnormal lateral pressure.

Signed by me, this 12th day of January,

JOHN R. MGGIFFERT. Attested by J J. LUMM, NINA G. NELSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

